| 1 | |
| 2 | /* Bring up a window and manipulate the gamma on it */ |
| 3 | |
| 4 | #include <stdlib.h> |
| 5 | #include <stdio.h> |
| 6 | #include <string.h> |
| 7 | #include <math.h> |
| 8 | |
| 9 | #include "SDL.h" |
| 10 | |
| 11 | /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */ |
| 12 | static void quit(int rc) |
| 13 | { |
| 14 | SDL_Quit(); |
| 15 | exit(rc); |
| 16 | } |
| 17 | |
| 18 | /* Turn a normal gamma value into an appropriate gamma ramp */ |
| 19 | void CalculateGamma(double gamma, Uint16 *ramp) |
| 20 | { |
| 21 | int i, value; |
| 22 | |
| 23 | gamma = 1.0 / gamma; |
| 24 | for ( i=0; i<256; ++i ) { |
| 25 | value = (int)(pow((double)i/256.0, gamma)*65535.0 + 0.5); |
| 26 | if ( value > 65535 ) { |
| 27 | value = 65535; |
| 28 | } |
| 29 | ramp[i] = (Uint16)value; |
| 30 | } |
| 31 | } |
| 32 | |
| 33 | /* This can be used as a general routine for all of the test programs */ |
| 34 | int get_video_args(char *argv[], int *w, int *h, int *bpp, Uint32 *flags) |
| 35 | { |
| 36 | int i; |
| 37 | |
| 38 | *w = 640; |
| 39 | *h = 480; |
| 40 | *bpp = 0; |
| 41 | *flags = SDL_SWSURFACE; |
| 42 | |
| 43 | for ( i=1; argv[i]; ++i ) { |
| 44 | if ( strcmp(argv[i], "-width") == 0 ) { |
| 45 | if ( argv[i+1] ) { |
| 46 | *w = atoi(argv[++i]); |
| 47 | } |
| 48 | } else |
| 49 | if ( strcmp(argv[i], "-height") == 0 ) { |
| 50 | if ( argv[i+1] ) { |
| 51 | *h = atoi(argv[++i]); |
| 52 | } |
| 53 | } else |
| 54 | if ( strcmp(argv[i], "-bpp") == 0 ) { |
| 55 | if ( argv[i+1] ) { |
| 56 | *bpp = atoi(argv[++i]); |
| 57 | } |
| 58 | } else |
| 59 | if ( strcmp(argv[i], "-fullscreen") == 0 ) { |
| 60 | *flags |= SDL_FULLSCREEN; |
| 61 | } else |
| 62 | if ( strcmp(argv[i], "-hw") == 0 ) { |
| 63 | *flags |= SDL_HWSURFACE; |
| 64 | } else |
| 65 | if ( strcmp(argv[i], "-hwpalette") == 0 ) { |
| 66 | *flags |= SDL_HWPALETTE; |
| 67 | } else |
| 68 | break; |
| 69 | } |
| 70 | return i; |
| 71 | } |
| 72 | |
| 73 | int main(int argc, char *argv[]) |
| 74 | { |
| 75 | SDL_Surface *screen; |
| 76 | SDL_Surface *image; |
| 77 | float gamma; |
| 78 | int i; |
| 79 | int w, h, bpp; |
| 80 | Uint32 flags; |
| 81 | Uint16 ramp[256]; |
| 82 | Uint16 red_ramp[256]; |
| 83 | Uint32 then, timeout; |
| 84 | |
| 85 | /* Check command line arguments */ |
| 86 | argv += get_video_args(argv, &w, &h, &bpp, &flags); |
| 87 | |
| 88 | /* Initialize SDL */ |
| 89 | if ( SDL_Init(SDL_INIT_VIDEO) < 0 ) { |
| 90 | fprintf(stderr, |
| 91 | "Couldn't initialize SDL: %s\n", SDL_GetError()); |
| 92 | return(1); |
| 93 | } |
| 94 | |
| 95 | /* Initialize the display, always use hardware palette */ |
| 96 | screen = SDL_SetVideoMode(w, h, bpp, flags | SDL_HWPALETTE); |
| 97 | if ( screen == NULL ) { |
| 98 | fprintf(stderr, "Couldn't set %dx%d video mode: %s\n", |
| 99 | w, h, SDL_GetError()); |
| 100 | quit(1); |
| 101 | } |
| 102 | |
| 103 | /* Set the window manager title bar */ |
| 104 | SDL_WM_SetCaption("SDL gamma test", "testgamma"); |
| 105 | |
| 106 | /* Set the desired gamma, if any */ |
| 107 | gamma = 1.0f; |
| 108 | if ( *argv ) { |
| 109 | gamma = (float)atof(*argv); |
| 110 | } |
| 111 | if ( SDL_SetGamma(gamma, gamma, gamma) < 0 ) { |
| 112 | fprintf(stderr, "Unable to set gamma: %s\n", SDL_GetError()); |
| 113 | quit(1); |
| 114 | } |
| 115 | |
| 116 | #if 0 /* This isn't supported. Integrating the gamma ramps isn't exact */ |
| 117 | /* See what gamma was actually set */ |
| 118 | float real[3]; |
| 119 | if ( SDL_GetGamma(&real[0], &real[1], &real[2]) < 0 ) { |
| 120 | printf("Couldn't get gamma: %s\n", SDL_GetError()); |
| 121 | } else { |
| 122 | printf("Set gamma values: R=%2.2f, G=%2.2f, B=%2.2f\n", |
| 123 | real[0], real[1], real[2]); |
| 124 | } |
| 125 | #endif |
| 126 | |
| 127 | /* Do all the drawing work */ |
| 128 | image = SDL_LoadBMP("sample.bmp"); |
| 129 | if ( image ) { |
| 130 | SDL_Rect dst; |
| 131 | |
| 132 | dst.x = (screen->w - image->w)/2; |
| 133 | dst.y = (screen->h - image->h)/2; |
| 134 | dst.w = image->w; |
| 135 | dst.h = image->h; |
| 136 | SDL_BlitSurface(image, NULL, screen, &dst); |
| 137 | SDL_UpdateRects(screen, 1, &dst); |
| 138 | } |
| 139 | |
| 140 | /* Wait a bit, handling events */ |
| 141 | then = SDL_GetTicks(); |
| 142 | timeout = (5*1000); |
| 143 | while ( (SDL_GetTicks()-then) < timeout ) { |
| 144 | SDL_Event event; |
| 145 | |
| 146 | while ( SDL_PollEvent(&event) ) { |
| 147 | switch (event.type) { |
| 148 | case SDL_QUIT: /* Quit now */ |
| 149 | timeout = 0; |
| 150 | break; |
| 151 | case SDL_KEYDOWN: |
| 152 | switch (event.key.keysym.sym) { |
| 153 | case SDLK_SPACE: /* Go longer.. */ |
| 154 | timeout += (5*1000); |
| 155 | break; |
| 156 | case SDLK_UP: |
| 157 | gamma += 0.2f; |
| 158 | SDL_SetGamma(gamma, gamma, gamma); |
| 159 | break; |
| 160 | case SDLK_DOWN: |
| 161 | gamma -= 0.2f; |
| 162 | SDL_SetGamma(gamma, gamma, gamma); |
| 163 | break; |
| 164 | case SDLK_ESCAPE: |
| 165 | timeout = 0; |
| 166 | break; |
| 167 | default: |
| 168 | break; |
| 169 | } |
| 170 | break; |
| 171 | } |
| 172 | } |
| 173 | } |
| 174 | |
| 175 | /* Perform a gamma flash to red using color ramps */ |
| 176 | while ( gamma < 10.0 ) { |
| 177 | /* Increase the red gamma and decrease everything else... */ |
| 178 | gamma += 0.1f; |
| 179 | CalculateGamma(gamma, red_ramp); |
| 180 | CalculateGamma(1.0/gamma, ramp); |
| 181 | SDL_SetGammaRamp(red_ramp, ramp, ramp); |
| 182 | } |
| 183 | /* Finish completely red */ |
| 184 | memset(red_ramp, 255, sizeof(red_ramp)); |
| 185 | memset(ramp, 0, sizeof(ramp)); |
| 186 | SDL_SetGammaRamp(red_ramp, ramp, ramp); |
| 187 | |
| 188 | /* Now fade out to black */ |
| 189 | for ( i=(red_ramp[0] >> 8); i >= 0; --i ) { |
| 190 | memset(red_ramp, i, sizeof(red_ramp)); |
| 191 | SDL_SetGammaRamp(red_ramp, NULL, NULL); |
| 192 | } |
| 193 | SDL_Delay(1*1000); |
| 194 | |
| 195 | SDL_Quit(); |
| 196 | return(0); |
| 197 | } |